Process for controlling the flow of metallurgical liquids



PROCESS FOR CONTROLLING THE FLOW Dec. 21, 1948. J. F. JORDAN 2,457,083

' OF METALLURGICAL LIQUIDS Filed June 27, 1947 I 2 Sheets-Sheet 1 Dec. 21, 1948.

Filed June 27, 1947 J. F. JORDAN PROCESS FOR CONTROLLING THE FLOW OF METALLURGICAL LIQUIDS 2 Sheets-Sheet 2 FIGJO INVENTORI- Patented Dec. 21, 1948 UNITED STATES PATENT OFFICE PROCESS FOR CONTROLLING THE FLOW OF METALLURGICAL LIQUIDS James Fernando Jordan, Huntington Park, Calif.

Application June 27, 1947, Serial No. 757,580

6 Claims. 1

This application is acontinuation-in-part of my copending application, Serial No, 681,253, filed on July ,3, 1946, now abandoned, and entitled: Method of controlling the flow of molten materia My invention relates to the control of molten metallurgical liquids.

The development of fully dynamic flow processes within metallurgy is handicapped in ways that did not handicap the development .of such flow processes in the chemical industries. The liquids employed in metallurgy are of such an erosive character that their mere confinement offers extreme difficulties; to say nothing of exercising a precise control over the flow of such liquids. It seems safe to predict that the development of flow processes in metallurgy will await the development of adequate methods of confining and controlling the flow of these erosive metallurgical liquids.

Metallurgists of the past and present have always been forced to depend upon non-metallic refractories as the means for confining and controlling these liquids. The expedient of frequent repair makes possible the commercial utilization of refractories in lining vessels which are to contain metallurgical liquids, however, refractories proffer little when it comes to controlling, say, the rate of flow of these liquids-it being impossible, seemingly, to construct a usable valve out of refractories. About the only valve that has ever been of value to metallurgists is the device that is known as the bottom-pour ladle; however, the'b0tt0m-p0ur ladle is impossible to control accurately, has an extremely short life, and has the bad habit of completely breaking down without warninga habit that can, and does, lead to rather disastrous results.

I have discovered a new and novel metallurgical valve. My valve not only solves the problem of controlling the flow of erosive liquids in metallurgy, but it may also be adapted to the task of confining these liquids. My valve consists of a refractory trough that possesses an adjustable gate consisting of a barrier of gas. My valve will hereinafter be referred to as the dynamic weir.

Figures 1-8, inclusive, are illustrations of a number of ways in which the dynamic weir may be used.

Figure 9 shows the weir being employed to confine two immiscible liquids.

Figure 10 shows the weir being employed to confine one liquid, while at the same time controlling the rate of flow of another liquid.

Figure 11 shows a section of Figure 9, as indicated.

Liquid confinement and control is simply a question of dams-even the sides of a furnace being nothing more than dams. A dam is a device that is employed to block the flow of a 1iquid. T he flow of a liquid could be effectively i 2 blocked with a curtain of high-velocity gas: an so, the dynamic weir.

It might be thought that if a curtain of highvelocity gas were to be projected into a liquid, that said liquid would be blown all over the place. Not necessarily; for, if a high-velocity gas stream is directed towards a liquid surface from a distance that is too far away to permit the gas stream to disturb the liquids surface, and then the orifice-to-surf ace distance is slowly shortened, it will be noted that the first visual effect of the impinging gas stream is the slight indentation of the liquids surface. It may be observed that this slight indentation possesses three features: (1) the indentation is shallow, (2) this shallow indentation is not associated with any surface indications of turbulence, and (3) the indentation degree is highly dynamic, that is, inasmuch as the depth of the indentation is a function of the energy content of the gas stream when it strikes the surface of the liquid, the slightest variation in the energy content of the gas streamobtained by varying the orifice-to-surface distance or by varying the gas pressure-will result in an instantaneous change in the indentation. As the orifice is brought closer and closer to the liquids surface, it will be noted that the indentation deepens as the energy of impingement mounts; and that, finally, an orifice-tosurface distance is reached where any further shortening of the distance will result in the destruction of the generally streamline character of the indentationsubstituting, in its stead, a violent turbulence or boiling action at the gas-liquid interface. The appearance of this turbulence at the gas-liquid interface signalizes the fact that the critical point in the action of these dynamic weirs has been reached; for, once turbulence sets in, the weirs cease to function properly.

Thus, the impinging gas curtain that constitutes a dynamic weir must possess a velocity that lies somewhere between zero and that critical velocity wherein turbulence ensues at th gasiquid interface.

Figure 1 shows a flowing stream of liquid upon which a column of high-velocity gas has been caused to impinge. Here, a gas under pressure X is operating against orifice 8/11). The energy released at the orifice is acting through distance B, to produce an indentationof depth D. The displacement of the liquid in the indentation represents the energy content of the gas stream when it strikes the surface 01" the liquidsaid energy being expended against the liquids viscosity. The highly variable character of this indentation is characterized by the fact that the indentation may be varied by varying the size of orifice S/D, by varying pressure X, or by varying distance D-all variations being, however, strictly Within those limits respecting turbulence, define-d previously.

In order to turn the device of Figure 1 into a Such an arrangement may be :used tcrdamea'l-iquim.

to confine a liquid, to maintain the level of a liquid, or to determine the rate of flow of a Iiquidl In Figure 2, S/W refers to :the width:- ot the:

elongated slit orifice, and'S/L refers to the length of said orifice.

It might be thought that the dynamic. weir could: not be.- employedto confine. and-control a deep. liquid stream. Such. is. not the. case. Figures? and 4. show two method-sot increasing thedepth to which. the weir willact. In .FigureS; increased penetration. is. obtained by increasing the width ofthe weir. This may be accomplished by, increasing the width or the: orifice whilemaintaining the gas pressure, or by increa-singdistance Bs'withsuitable pressure adjustments. trate: if the weir does not penetrate deep. enough into theliquid, even though it: may be operating close. to the critical level, distance B may be; increased by some selected-amount, followed by increases in pressure X until the desired penetration-isreached, or until the critical level is reached again. If the critical leve'lisreached. beforethe desired measure of penetration: is attain-ed, distance B may be increased again, followed by, further-increases in pressure X. These. adjustments I.

may becontinuedindefinitely. Ifiit is impractical to-increasedistance B, we may-increase theorifioe size instead, varying the pressure to. obtain the desired penetration.

Figure 4 illustratesthe fact that theseweirs may be employed in an additive-sense. Naturally; the use of. multiple weirs is effective only if the liquid is flowing. Any depth of: liquid may be penetrated by merely employing a. sufiicient number of'weirs.

I Figure 5' shows a use of the dynamic weir. for the purpose of confining ailiquid-in this case, a slagth atis floating on a metal. It. will benoted that the .gascurtain or barrier penetrates entirely through the slag layer andipartly intothe-underlying metal layer.

Figure 6 shows-that these weirs maybe sub-divided into aseries of conveniently sized gates;.each gate being independently controllable, both with regards to pressure X and distance B. With the Weir so subdivided, a variety of conditions may be setup across the dam. In Figure 6, for-example, gate #2 is adjusted to act as a free-flowing sluice. Naturally, control over this free-fiowingsluice may be obtained by merely regulatingv pressure X and/or distance B in gate #2.

, Figure 7 shows a sluice operating under restraint. Here, gate #2 is shown impressin a measure of control over the stream. It will benoted, atthe other end of the illustrated body of liquid, that another type of weir is operating'imvmediately adjacent to-the incoming liquid. This weir. merely serves to' show that more than one weir. may be employed in the same liquidsystem at the .same time, and with each weir performing the same or difierent functions.

Figure 8 shows that these weirs neednot necessarily be confined-to straight dams. Thus, as in Figure 8, the weir maybe caused to operate inla widesweeping-curve.

Figure 2 shows such an extension To 7 illus- The gas The gas employed in their weirs is merely a means to an end-an end characterized by/the mechanical nature of the confinement and'control of viscous liquids. tion of the weirs is concerned, any gas may be employed 120.801517531718 these gas dams. In general, a asmust be'selected that does not interfere with the chemical aspects of the operation that is being carried on. Ifran oxidizing gas is objectionable, eithera neutral or reducing gas may be emp1oyed;.;if a reducing gas is objectionable, either a neutral or oxidizing gasmay be employed; or if strict neutrality is desired, a neutral nitrogen, may: beemployed- These gas weirs: may be used" to attain' specific chemical ends... For example, if an: effort-labe ing; made to. oxidize the impurities in, say; steel the gas employed in the weirs may be air,..car bson: dioxide, oristeam; If, on theother hand, an effort is being made to reduce, say, the.Gl12 content of copper; the gasemployed in-theweir could be canbenmonoxide.

Dynamic weirs: may be. caused: to, contribute heat toth'e passing liquid, or comerselyrtheeweirs may'detract heat; fromithe liquid; With metaliurgicali liquids; the test for the feasibilityof employing cold' gases in theweirs. will depend upon the chilling efiect. of. the.-ga-s;. in terms of B. t;.u; per second' inrelatien. to the available or expendable heatin: the liquid". that passesby the weirduring. this: interval; Thus, if: ametallurgiicalsliquidzcontains, say, 70.0 B: t. u; per-pound, and the nature of the liquid and operation-Willpermit this heat content: to. fall to; say, 60d Bi. tin per pound; without operating difliculties: developing asiaz consequence; then thetliquidzmay be dammed by? a. cold gas; weir. if the weir does-not remove more than 1D0"B ;.:t. u. per pound: fliquid.

If thealiquid. does not.possess;sufiicientiexpend ableil'ieat. to permit: the operation: ofia cold gas weir, then. the flame weirmay be employed; The flameweir employs; a combustible mixture-of fuel gas: and air/oxygen; and will accordingly contribute heatto: tnealiquid that is being controlled:

The weir The dynamic weir; may be constructediin: any number of ways; but must possess: 3213. least one method: of regulating the-strength of theibarrier Off gas, I prefer aiweir thatpossessesxtwo' control methods, that it,.a weir with. avalve that-controls the velocity; or the,- gas. the: barrier; and: also possesses-the. means. for: raising and'lowering the orifice from :whichthe :gasimm'erges. 1

Figure9 showsa weir that possesses bothregulating, methods.- Here, weir: 245 is 1 actingto confine liquids;,25 and-.26; on: hearth 21; The work thatiybeing doneiby weir 24'is;re1ated;to=the positionrof orifice. 23controllable by raisingzor lowering: means: 2l-.-and'; is also rel'atedr to the pressure-of gaszfl against orifice Z3; variable by regulating valve 19. Figure 11 shows another view of the-:opera-tion. illustrated: in Figure 9. Here, hearth 21 and sidewallszk combine with means 2t to, forma weir. Orificev Z3 is the source of. theweir gas that acts to. dam liquids. 25- and iii (not shown);

Figure 10 shows another.- use' to P which. the weir I Insofar as the purely physical acv gas, such as lating both the Vertical position and the pressure.

Due to the fact that metallurgy usually concerns a molten metal upon which a molten slag is caused to float for refinement purposes, liquid 25 should be considered to be a slag and liquid 26 a molten metal.

Any convenient valve system may be employed to regulate the pressure of gas 20 against orifice 23. Any convenient method may also be employed to raise and lower means 2|-I prefer a rack and pinion. I prefer to maintain the pressure of gas 20 constant against orifice 23, and obtain control by raising and lowering means 2|.

If the metallurgical operation is a high temperature one, means 2| should be water-cooled with appropriate water-jackets.

The expression orifice, as used in the claims, shall be taken to mean any opening, or any group of openings, down through which high-velocity gas may be fed to form a barrier in a refractory trough.

The expression substantially horizontal flow, as used in my claims, shall be taken to mean liquid flow along an open channel wherein the stream possesses a free surface.

Having now described and illustrated one form of my invention, I wish it to be understood that my invention is not to be limited to the specific form or arrangement of parts herein described and shown, except insofar as such limitations are specified in the appended claims.

I claim as my invention:

1. In the process of conducting a metallurgical liquid along a refractory trough, the method of controlling the rate of flow of said liquid along said trough, which comprises: jetting down into said fiowing liquid, from an orifice that is positioned above the free surface of said liquid, a barrier of gas that forms an indentation in and across the flowing liquid stream, and thereby blocks the free flow of said liquid stream; and controlling the rate of flow of said liquid stream by regulating the pressure exerted by said barrier on said liquid stream in the range between zero and that pressure at which a boiling action ensues at the liquid-gas interface, by regulating the pressure at which the gas is supplied to said orifice.

2. In the process of conducting a metallurgical liquid along a refractory trough, the method of controlling the rate of flow of said liquid along said trough, which comprises: jetting down into said flowing liquid, from an orifice that is positioned above the free surface of said liquid, a barrier of gas that forms an indentation in and across the flowing liquid stream, and thereby blocks the free flow of said liquid stream; and controlling the rate of flow of said liquid stream by regulating the pressure exerted by said barrier on said liquid stream in the range between zero and that pressure at which a boiling action ensues at the liquid-gas interface, by selectively raising or lowering said orifice.

3. In the process of conducting a metallurgical liquid along a refractory trough, the method of controlling the rate of flow of said liquid along said trough, which comprises: jetting down into said flowing liquid, from an orific that is positioned above the free surface of said liquid, a barrier of gas that forms an indentation in and across the flowing liquid stream, and thereby blocks the free flow of saidliquid stream; and controlling the rate of flow of said liquid stream by regulating the pressure exerted by said barrier on said liquid stream in the range between Zero and that pressure at which a boiling action ensues at the liquid-gas interface.

4. In a, liquid-liquid system consisting of a stream of molten metal upon which a molten slag is floating, the method of confining the molten slag while controlling the rate of flow of the metal stream, which comprises: jetting down into said slag, from an orifice that is positioned above the free surface of said slag barrier of gas that forms an identation in and across the surface of said slag, which indentation penetrates entirely through said slag and into the underlying metal stream, thereby confining said slag while blocking the free flow of said metal stream; and controlling the rate of flow of said metal stream by regulating the pressure exerted by said barrier on said metal stream in the range between zero and that pressure at which a boiling action ensues at the liquid-gas interface, by selectively raising or lowering said orifice.

5. In a liquid-liquid system consisting of a stream of molten metal upon which a molten slag is floating, the method of confining the molten slag While controlling the rate of flow of the metal stream, which comprises: jetting down into said slag, from an orifice that is positioned above the free surface of said slag, a barrier of gas that forms an indentation in and across the surface of said slag, which indentation penetrates entirely through said slag and into the underlying metal stream, thereby confining said slag while blocking the free fiow of said metal stream; and controlling the rate of flow of said metal stream by regulating the pressure exerted by said barrier on said metal stream in the range between zero and that pressure at which a boiling action ensues at the liquid-gas interface, by regulating the pressure at which the gas is supplied to said orifice.

6. In a liquid-liquid system consisting of a stream of molten metal upon which a molten slag is floating, the method of confining said slag while controlling the rate of flow of said metal stream, which comprises: jetting down into said slag, from an orifice that is positioned above the free surface of said slag. a barrier of gas that forms an indentation in and across the surface of said slag, which indentation penetrates entirely through said slag and into the underlying metal stream, thereby confining said slag while blocking the free flow of said metal stream; and controlling the rate of fiow of said metal stream by regulating the pressure exerted by said barrier on said metal stream in the range between zero and that pressure at which a boiling action ensues at the liquid-gas interface.

JAMES FERNANDO JORDAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Certificate of Correction Patent No. 2,457,083 December 21, 1948 JAMES FERNANDO JORDAN It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 5, line 68, for orific read orifice; column 6, line 10, for the Words slag barrier read slag, a barrier;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oflice. Signed and sealed this 3rd day of October, A. D. 1950.

[SEAL] THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

